Overall leader Christopher Froome, with yellow helmet, trains with his teammates on Monday’s rest day at the Tour de France in La Baule, France.

SAINT-NAZAIRE, France — The manager of Chris Froome’s team promises that his star rider will never again be left exposed in his bid to win the Tour de France.

Froome kept the yellow jersey on a ferociously tough mountain stage Sunday. The British rider will wear it when the race resumes Tuesday with Stage 10 following Monday’s rest day.

That Froome had to defend the jersey alone in the ninth stage — because all his Sky teammates had been left behind — offers hope to rivals like two-time champion Alberto Contador and Andy Schleck. If they can again isolate Froome later in the race, perhaps he will be too tired to respond.

“We’ve learnt some lessons, valuable lessons, to take into the rest of the race,” Sky manager Dave Brailsford said Monday. “But I’m not going to spell it out. I’m not going to go into the details of the changes we’re going to make.”

Froome’s key teammate is Richie Porte, an Australian who won the Paris-Nice stage race in March. He was unable to help Froome on Stage 9 and wants to make amends.

“Am I going to have another bad day like that? I hope not,” he said.

Contador, the Tour winner in 2007 and `09 who was stripped of his title the following year for doping, is looking forward to getting another shot at Froome in the mountains Sunday.

“I will try and do something,” Contador said. “If you don’t think you can succeed then you never will. So we have to take a few risks.”

Sunday’s 15th stage is the next big climbing trek and features a 12.9-mile ascent to Mont Ventoux. A few days later, riders face three straight days of arduous mountain climbing in the high Alps.

“Throughout my career I’ve found my best form in the third week,” Contador said.

The 30-year-old Spaniard takes heart from winning the Spanish Vuelta last year, a race in which Froome finished about 10 minutes behind in fourth place.

“People can speculate and look at my previous performances however they like, but I look at that Vuelta in that I was running on fumes. I was in survival mode,” Froome said. “If people want to make comparisons that’s up to them, but I don’t feel I was at my best.”

Tuesday’s stage is a 122-mile route from Saint-Gildas-des-Bois to Saint-Malo and is made for sprinters. On Wednesday, Contador could face trouble in the 20.5-mile time trial.

“It’s a very flat time trial and that is a disadvantage for me,” he said.

Froome finished second to Tour winner Bradley Wiggins in the time trial last year and is considerably faster than Contador. The Spaniard may be able to limit the time gaps this time because the dash from Avranches to Mont-Saint-Michel is relatively short.

Given the way Froome is riding, he can take a big step toward winning the Tour if he extends his overall advantage after the time trial.

Spain’s Alejandro Valverde is 1 minute, 25 seconds behind Froome. Contador is 1:51 behind in sixth, while Schleck is four minutes back in 15th place, and Evans trails by 4:36 in 16th place.

None will be consoled by last year’s race. Valverde was a massive 7:20 slower than Froome in last year’s 33.2-mile time trial; Evans was 4:28 slower. They again face the prospect of losing significant time to Froome.

This is the 100th edition of the Tour and the first since Lance Armstrong was stripped of his seven straight titles from 1999-2005 for serial doping.

Froome has said twice during the race that he is riding clean. Contador again repeated that he has never doped, even though he tested positive for the banned drug clenbuterol.

“Naturally people are going to ask questions in cycling,” Froome said. “Whenever there are great performances they have been linked to doping in the past, so naturally now we’re bearing the brunt of a lot of those questions.”

Contador, who lost his 2010 title to Schleck, has always denied doping.

“You can believe what you want,” he said. “But the only thing that I can tell you is that I have always practiced cycling clean.”

Froome would not be drawn on Contador’s comment, other than saying: “There definitely do need to be questions asked about performances in the past.”